1. Field
The described embodiments relate to techniques for controlling power usage for a portable electronic device. More specifically, the described embodiments relate to techniques for controlling low-power Wi-Fi roaming in a portable electronic device.
2. Related Art
An important feature of many portable electronic devices, such as smartphones and tablet computers, is the ability to communicate packet data to enable activities such as sending and receiving emails or browsing the Internet. Often, portable electronic devices may communicate such packet data using either a wireless local area network (WLAN) connection (such as a Wi-Fi connection to a Wi-Fi network) or a cellular data connection to a cellular packet data network (such as a 3G or 4G network). However, communicating packet data to and from a portable electronic device consumes power, and because many portable electronic devices are powered by batteries, reducing power consumption while still enabling the communication of packet data may increase the length of time the portable electronic devices can be used before recharging the battery and, thus, may help improve the user experience.
To save power, it is preferable to use a Wi-Fi network instead of a cellular packet data network because the Wi-Fi circuitry within a portable electronic device typically consumes less power than the circuitry used to support the cellular packet data network. However, in order to maintain a Wi-Fi connection, a portable electronic device typically needs to perform periodic roaming operations to detect available access points (APs), and these roaming operations can consume a considerable amount of power.